β-catenin is a major tyrosine-phosphorylated protein during mouse oocyte maturation and preimplantation development
✍ Scribed by Mami Ohsugi; Stefan Butz; Rolf Kemler
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 528 KB
- Volume
- 216
- Category
- Article
- ISSN
- 1058-8388
No coin nor oath required. For personal study only.
✦ Synopsis
During mouse preimplantation development, the components of the E-cadherincatenin complex are derived from both maternal and zygotic gene activity and the adhesion complex is increasingly accumulated and stored in a nonfunctional form, ready to be used for compaction and the formation of the trophectoderm cell layer (Ohsugi et al., Dev. Dyn. 206:391-402, 1996).
Here, we show that -catenin is a major tyrosine-phosphorylated protein in oocytes and early cleavage-stage embryos and that the relative amount of phosphorylated -catenin is greatly reduced during the morula-blastocyst transition. Peptide-specific antibodies indicate that -catenin undergoes conformational changes and/or that the carboxy-terminal region of -catenin is blocked during preimplantation development. Moreover, the availability of a carboxy-terminal epitope seems to depend on the tyrosine phosphorylation state of -catenin and becomes unmasked when oocytes are treated with the tyrosine kinase inhibitor genistein. Our results suggest that tyrosine phosphorylation of -catenin represents a molecular mechanism to keep the accumulating E-cadherin adhesion complex in a nonfunctional form.